Born in Paris, France, the son of an Italian engineer, Émile Zola spent his childhood in Aix-en-Provence and was educated at the Collège Bourbon. At age 18 he would return to Paris where he studied at the Lycée Saint-Louis. After working at several low-level clerical jobs, he began to write a literary column for a newspaper. Controversial from the beginning, he did not hide his disdain for Napoleon III, who used the Second Republic as a vehicle to become Emperor.

More than half of Zola's novels were part of a set of 20 collectively known as Les Rougon-Macquart. Set in France's Second Empire, it traces the hereditary influence of violence, alcoholism, and prostitution in two branches of a family, the respectable Rougons and the disreputable Macquarts, for five generations.

As he described his plans for the series, "I want to portray, at the outset of a century of liberty and truth, a family that cannot restrain itself in its rush to possess all the good things that progress is making available and is derailed by its own momentum, the fatal convulsions that accompany the birth of a new world."

Zola and the painter Paul Cezanne were friends from childhood and youth, but broke in later life over Zola's fictionalized depiction of Cezanne and the bohemian life of painters in the his novel L'Oeuvre (The Masterpiece,1886).

He risked his career and even his life on January 13, 1898 when his "J'accuse" was published on the front page of the Paris daily, L'Aurore. The paper was run by Ernest Vaughan and Georges Clemenceau who decided that the controversial story would be in the form of an open letter to the President, Félix Faure. J'accuse accused the French government of anti-Semitism and wrongfully placing Alfred Dreyfus in jail. Zola was brought to trial for libel for publishing J'Accuse on February 7, 1898 and was convicted on February 23. Zola declared that the conviction and transportation to Devil's Island of the Jewish army captain Alfred Dreyfus came after a false accusation of espionage was a miscarriage of justice. The case, known as the Dreyfus affair, had divided France deeply between the reactionary army and church and the more liberal commercial society. The ramifications would continue for years so much so that on the 100th anniversary of Émile Zola's article, France's Roman Catholic daily paper, "La Croix", apologized for its anti-Semitic editorials during the Dreyfus affair.

Zola was a leading light of France and his letter formed a major turning-point in the Dreyfus affair, causing the captain's case to be reopened, whereupon he was acquitted. In the course of events, Zola was convicted of libel and sentenced himself and removed from the Legion of Honor. Rather than go to jail, he fled to England to escape imprisonment. Soon he was allowed to return in time to see the government fall. Dreyfus was convicted again, but was ultimately freed, in large part due to the moral force of Zola's arguments. Zola said "The truth is on the march, and nothing shall stop it." In 1906, Dreyfus was entirely exonerated by the Supreme Court.